Assuming you are creating a Web App, remember that uploading a file (any file, not just images), is a mechanism that is dicated by how the browser and HTML works, and not so much by how OutSystems specifically handles things. The way it works is that you select a file using the Upload Widget, and when you do a Submit (e.g. via a Button), the browser loads the file, and sends it to the server. On the server, your Web App's code runs, so that's the moment you can inspect things like the filename (to check for an allowed extension) or the file's size.

The Upload Widget has three Properties associated with it: Content (the actual binary content of the file), the Type, which is the MIME type (e.g. image/jpeg) and Filename, the name of the file:

You can check the size of the file by using the BinaryDataSize Action from the BinaryData Extension. You can check it's extension by checking the filename, but if you only allow images it's better to use the Type for the MIME type (you can Google the MIME types for other image types).

Assuming you are creating a Web App, remember that uploading a file (any file, not just images), is a mechanism that is dicated by how the browser and HTML works, and not so much by how OutSystems specifically handles things. The way it works is that you select a file using the Upload Widget, and when you do a Submit (e.g. via a Button), the browser loads the file, and sends it to the server. On the server, your Web App's code runs, so that's the moment you can inspect things like the filename (to check for an allowed extension) or the file's size.

The Upload Widget has three Properties associated with it: Content (the actual binary content of the file), the Type, which is the MIME type (e.g. image/jpeg) and Filename, the name of the file:

You can check the size of the file by using the BinaryDataSize Action from the BinaryData Extension. You can check it's extension by checking the filename, but if you only allow images it's better to use the Type for the MIME type (you can Google the MIME types for other image types).

Ok, I'm sending an example, but for replicate this you need in your app go to manage dependencies, search for BinaryData click on it and you will need to check the BinaryDataSize in order to use it to get the size of your file, it will return the size in bytes so have that in mind when you use it. The remain is very self-explanatory, just see it in the UploadPhoto action of the PersonDetail screen.